14 - GAZ 47-AMA of A. M. Avenarius in 1965. Pict J M M Archives.

15 - GT-TK of A. M. Avenarius in 1974.

The first patent for caterpillar (Photo 1) comes from Mr. Hermand in 1713 (Memoir No. 142 presented at the Academy of Sciences, France). It may be noted in this patent a series of rollers assembled but the track as we know it today is different, its design dating from the mid-19th and early 20th century, as if d'Hermand had invented in the starting 'Airoll' concept resumed 250 years later.

After a jump in time and several patents later, we found a U.S. patent No. 2.734.476 of February 16 1956 describing a kind of raft equipped with rollers (Fig. 2). There was no prototype. It came only in 1962 with the Airoll MVT, Marginal Terrain Vehicle. The MVT were experimental vehicles in the 60s and 70s able to travel on land classified as marginal as they were impassable to vehicles already existing.

1 - Airoll : The first simplified working prototype called Airoll (photo 3), was established in June 1962 by Ingersoll Kalamazoo Division of Borg Warner and the U.S. Navy. After testing, this system was considered the first vehicle outperforming the wheel and the caterpillar. Sixteen tires 'Terra Tires' attached to chains driven by large diameter sprockets rotated freely. The lower tires were pressed between the pontoons and the ground. To move through half-liquid deep mud, swamps, snow and sand, the rollers did not turn over but always moving in translation and acted as paddle wheels. It was reported that the device behaved better than any known vehicle in the mud almost liquid. Powered by a Chrysler V8 engine and weighting 9 t, it could travel at 50 km / h on land and 16 on the water.

2 - Airoll I : The Borg-Warner Corporation and the U.S. Marine Corps in 1965 presented a more elaborate version, narrower and practice, the Airoll I (photo 4), equipped with 13 tires on each side, mud guards, position lights and windshield. With a capacity of half a ton and tested extensively on 15.000 km, this achievement was rather successful. With excellent capacity on soft soil and water, the lateral stability and reliability should be improved. Known also as the 'Water Skipper' or LVA-X1, it remains to our knowledge a copy to the USMC Museum in Quantico, Maryland.

3 - XM 759 : The U.S. Army took the idea and ordered the XM759 Marginal Terrain Vehicle (photos 5-6-7-8) to Pacific Car and Foundry. It weighed 4.2 tones for a payload of 1.4 tones, length 6.2 m, wide 2.8 m and 17 tires on each side.

USMC bought 7 more, better equipped to test and manufactured between February and March 1967. The XM 759 could carry 14 fully equipped men plus 2 crews. The features were : ground pressure 0.15 kg/cm2, tank 223 l and 260 km of autonomy, maximum gradient 60% and side slope 30%, crossing a vertical wall of 0.9 m and a trench 2 m wide. It was self recovery with capstan heads bolted on the front sprockets or rear wheels. The engine was located behind the cab.

It can be seen (photo 5) that of the Museum of Pendelton and another in a private collection (photo 6) in Northern California.

4 - Canadair Fisher : A small civil ATV (All Terrain Vehicle), Fisher-Canadair CL-213 or X-209 (Photo 9-10-11) was built in 1963 and 1964 by a defector from Ford, Montrealer A. Gordon Fisher. Equipped with a single cylinder Rotax 9 hp, it had a payload of 250 kg for a total weight of 362 kg and a speed of 19 km/h on land and 4 km/h on water. Its uniqueness is of course that it incorporated Airoll system propulsion with 7 tires on each side, which gave very good all terrain performance . Two were built one for the U.S. Army who tried from March to July 1967 and called for a larger version.

5 - Dredge : The Dredge (photo 12), built in 1967 by Development Division of Clark Equipment Co., Cassoplis, Michigan, for U.S Forest Service, Portland, Oregon, used the same method of propulsion. Completely refurbished in 1983, it was used for a year for maintenance of a pond. With 4 hydraulic winches, two large pumps, two Buick V6 engines and an aluminum body, it was also amphibious.

6 - USSR : The Russians too had their 'Airoll'. The Studies Office of Zil edited by B. A. Grachev conceived in 1965 a machine type 'Airoll', the ZIL PKTs-1 (photo 13). It was considered too large, too heavy and lacking stability in the verse, consuming too much and wear out quickly.

But Alexander Mikhailovich Avenarius had proposed a system with gear wheels-tracks in 1942 and again in 1950 without much success. Avenarius calls on the ZIL plant in Moscow in 1965 to create the GAZ47-AMA (photo 14) tried but discarded as scrap. By no means removed, it realizes the KV-1 and 15 years later, the KV-1M weighting 1-ton equipped of tracks with rollers of 25 cm and then in 1974, a transport GT-TK of 10 t (photo 15) with rollers of 32 cm. Tests on hundreds of miles were made in 1975-76 on the most diverse land and proved very successful. In addition, this system did not deteriorate as much soil a classic track.

The mechanism 'Airoll' was not series produced despite its qualities. They found it cumbersome and unreliable, although these defects could be corrected. Many other modes of off-road transportation were invented and tried both the imagination of inventors and engineers are fertile, but it's that one which, beyond its originality, is closest to the final stage of mass production.